The field of the present invention is lamps.
Lamps have been manufactured which include a sealed tube with a septum extending through the major length of the tube cavity. The cavity on either side of the septum is connected at the distal end of the tube. Electrodes are placed on either side of the septum and energized so that gas throughout the tube cavity on either side of the septum generate electromagnetic radiation.
Specialty lamps of this type have been made which include a bend in the lamp tube. The bend is accomplished through a heating of the glass tube. To avoid cross-sectional shrinking of the heated tube during bending, the bend is made before vacuum is drawn on the tube. The electrode is then placed in the tube with the bend between the electrode and the distal end of the tube. A vacuum is then drawn on the tube with the electrode assemblies loose in the tube between the terminal end of the tube and the bend. The tube is heated around a portion of the electrode assemblies to shrink the tube in cross section under the influence of the vacuum inside. This operation sets and seals the tube around the electrode assemblies. The terminal end of the tube may then be cut off to expose one end of the electrode assemblies.
Such conventional lamps work satisfactorily when properly formed. However, the bending process can crimp the tube and cut off the desired communication between electrodes through the lamp cavity. Under these circumstances, the lamp is a reject. Also, because the ends of the electrodes are before the bend, light is frequently generated in the bend. This is undesirable and under certain circumstances can lead to rejection of the lamp. Significant costs accrue in either avoiding rejects in detailed manufacture or manufacturing and discarding rejects.